Post G23-053: It’s a beautiful day in the neighborhood.

 

Today feels like a fine autumn day, here in Vienna, VA.  So I thought I’d write something unalloyedly nice.  On the screen porch, feet up, sipping iced tea.

Listening to the katydids sing.  As I type.

Or whatever those damned bugs are.  Maybe the right name is locusts, but locusts get such a bad rap that I’ll cut them some slack and call them something nicer.  You might find that loud chirruping annoying, where you live.  But where I live, the katydids are Nature’s white noise machine.  They mask what would otherwise be unrelenting traffic noise, lawn mowers, leaf blowers, and so on.

I say autumn day, because the air is cool and the humidity is low.  After the heat and humidity of summer, this is a welcome change.  So it feels like fall, even if the autumnal equinox is still almost a month away.

Here are my observations on three nice things that are happening in my garden. Continue reading Post G23-053: It’s a beautiful day in the neighborhood.

Post G23-052: I dried my underwear in my food dehydrator.

 

I know what you’re thinking.  You’re thinking “Hey, dummy, that’s what the microwave is for.”

And while I acknowledge the truthiness of that statement, my excuse is that I baked my briefs in this manner for Science.

This post focuses on a seemingly simple question:  Why is an electric food dehydrator such an incredibly energy-intensive way to preserve food?

The answer is unsatisfying.  In roughly equal parts:

  • Evaporating water is energy-intensive
  • Evaporation water out of food is even more so.
  • My particular dehydrator is somewhat inefficient.

My bottom line is that drying a pound of wet produce, in my electric dryer, under optimal conditions, takes about 2 kilowatt-hours of electricity.  And there ain’t much I can do about that, other than coming up with a solar dryer that will function in my climate.  My first attempt at that turned out mediocre (Post G22-015).

Continue reading Post G23-052: I dried my underwear in my food dehydrator.

Post #1843: Why are ceiling fans vastly more efficient than box fans?

 

In a nutshell?  To provide the same flow (CFM or cubic feet per minute), a small fan (like a box fan) has to move air a lot faster than a larger fan (like a ceiling fan).  And to move air fast, it takes disproportionately more pressure — and hence energy — than it takes to move it slowly.

The rest is just arithmetic.

I’m not talking slightly more efficient.  It’s well-established that ceiling fans are the most efficient type of home fan you can buy (reference).

I’m talking on-order-of five times as efficient as a box fan.  That, comparing the elderly ceiling fans in my house, against the most efficient modern box fan currently sold at Home Depot.

My main point is that the efficiency advantage of ceiling fans is rooted in basic physics.   It’s purely a consequence of their larger size.  It has nothing to do with (e.g.) the grilles on the box fan or the efficiency of various styles of electric motors.  It is simply that to achieve some given rate of air movement (cubic feet/minute), it takes far less energy to move a large volume, slowly, than to move a small volume, quickly.

Not only are ceiling fans more efficient than box fans, they always have been, and always will be.  It’s not the motor, or the housing, or the grille, or any of that.  It’s just physics.

Edit:  This also explains why bathroom fans are so slow at clearing the air.  If you wanted a bathroom fan that could move as much air as a box fan, it would require a 500 watt motor (Post #1859).

 

Continue reading Post #1843: Why are ceiling fans vastly more efficient than box fans?

Post #1841: Used electric vehicle prices are plummeting?

Caveat emptor.

It has been a long time since I last bought a used car. 

I have forgotten just how sleazy the low end of the used car market can be.

But I’m getting educated in a hurry.

Today’s lesson in low-end used cars?  A few weeks back, I was interested enough in an older Nissan Leaf that I scheduled an appointment with the dealer, to have a look at it.  Then I did my homework, and cancelled the appointment.

And, foolish me, I figured I at least owed the guy an explanation of why I wasn’t interested.  Because that’s what reasonable people do.

The ad for the car claimed excellent battery health, and a 110-mile range, per the independent estimate from Recurrent.com.  By contrast, once I learned to read the “gas gauge” of a Nissan Leaf, photos of the dashboard revealed barely 60 miles of range left, as well as a battery that was in mediocre health.  Via email, I told the dealer that’s why I was no longer interested.  The car really didn’t have adequate range left.

I continue to track the ad for that car, just to try to get a handle on the used car market.

In response to my explanation of that cancelled appointment, what do you think the used car dealer did to the ad for that car?

  1. Nothing.
  2. Removed the falsely inflated range estimate from Recurrent.com
  3. Removed the photos of the car that revealed the actual range.

If you guessed “c”, then you’re a lot less naive about the used car market than I am.  Or was.

As an economist, I really shouldn’t use the word “sleazy”, when the behavior is rational.  The dealer represents seller, plain and simple.  The dealer’s job is to get the best price for the seller, within some reasonable timeframe.  Anything that  increases the odds of selling the car, without getting thrown in jail, is fair game.  So, if fuzzying-up the information on range might help sell the car, then fuzzying should occur.  It’s up to the buyer to understand that and act accordingly.

In fairness, the dealer keeps dropping the price of that 2016 Nissan Leaf.  In any case, I’ve already made up my mind that I don’t want anything earlier than a 2018 Leaf, due to the rapid degradation of the battery in earlier model years of Leafs.

The lesson here is that it’s still a used car, even if its electric.  With everything that buying a used car entails.  Just because it’s eco-friendly doesn’t mean the dealer is friendly.  The upshot is that in trying to be a straight shooter, in a room full of crooks, all I did was help the crooks to be better crooks.


My local used EV market still appears too hot for my liking.

In addition to that 2016 Leaf, I have been tracking three 2018-or-later Leafs.  These have a different battery chemistry from older Leafs.  They retain their battery health and range much better than the pre-2018s and are priced accordingly.

Of the three cars I begin tracking less than two weeks ago, two have already sold.

Assuming that’s not just some kind of fluke, either I have an exceptional eye for a good deal, or the market for a reliable used EV is pretty hot.  At least around here. 


But the internet assures me that used EV prices are plummeting.

Official U.S. Consumer Price Index data are all-but-useless for judging long-term trends in the price of new and used cars.  I went through that in Post #1836.

Source: Bureau of Labor Statistics, via the Federal Reserve of St. Louis FRED system

The quality adjustment embedded in the CPI car price data mean that the price trends as published by the Bureau of Labor Statistics have nothing to do with how much money you’ll need to shell out to buy a basic car.  Such as Toyota Corolla, shown in yellow below.

But if car prices move fast enough, the actual change in prices will swamp the BLS quality adjustments.  And so, for sharp short-term price movements, the BLS data aren’t too bad.  From the BLS, we can see that used car prices peaked at the end of 2021, and have been mostly falling since.

Source:  Underlying data from the St. Louis Federal Reserve (FRED)

The BLS does not appear to publish any data separating electric vehicles from other types of vehicles.  So I have to turn to privately-produced price statistics if I want to get a handle on what’s happening to EV prices, as distinct from other types of vehicles.

And that’s where things turn a bit odd.  Because, as far as I can tell, a lot of private-sector price estimates show that the price of used EVs is plummeting.

Here are two such estimates, from what I believe to be independent data sources:

The devil is in the details.

The iSeeCars study is a study of used cars one to five years old.  And the measured price reduction in that segment was driven by Tesla’s decision to cut the price of its new cars.  More-or-less, what they measured is that the price of used Teslas fell about 30%.  In addition, it appears that they do not adjust for changes in the mix of vehicles sold, but simply take the change in the average asking price for a used EV.

The Recurrent study is also a study of used cars one to five years old.  It appears to be based on the simple average of the asking prices of seven common used EVs and PHEVs.  And, as with the iSeeCars study, a big chunk of the reduction is attributed to Tesla’s decision to cut the price of their new cars substantially.

That said, the Recurrent study shows a corresponding increase in (e.g.) the fraction of the used EV market offered for sale at less than $25K.  I’m pretty sure that excludes most Teslas.  The inference would be that these price declines affected the broader market, not just Tesla.


I’m still in no particular hurry to buy.

When all is said and done, my guess is that I should be in no hurry to buy a used EV.  Prices for relatively new models (one-to-five years old) appear to be falling, in large part due to new-car price cuts by market leader Tesla.  I don’t perceive that among low-end models, in my geographic area.  But its possible I simply tracked an unusual small sample of cars.

Although the price trends may be murky, one aspect is clear.  I’m still something of a babe in the woods when it comes to buying a used EV.  I need to get a lot smarter before I put my money down on a used car.  Even if it is an eco-friendly electric car.

Post #1837: Note to self: Get a 2018 or later Nissan Leaf

 

Edit 1/21/2024:  Between the time I wrote this, and January 2024, the price of used Chevy Bolts dropped so much that, in the end, I ended up buying a 2020 Chevy Bolt.  See Post #1924 for the reasoning behind that.

I continue to stumble across important facts about used EVs.

In this case, it’s that the 2018 (and later) Leaf is vastly better than earlier models.  That’s because Nissan finally scrapped its older, inferior battery chemistry that year.

Unsurprisingly, used Leaf prices seem to reflect that.

Continue reading Post #1837: Note to self: Get a 2018 or later Nissan Leaf

Post #1836: Will used-car prices continue to fall?

 

Warning:  This post contains economics.  It’s about the odd state of the used car market, right now.  And my guess that used car prices will continue to trend down from their December 2021 peak.

Update one year later, 7/26/2024:  At this point, the post-pandemic spike in used-car prices has pretty much run its course.  In real (inflation-adjusted) terms, used car prices are only slightly higher than they were before the pandemic.  Therefore, I’d guess that there’s not much potential for them to fall much further.

Here’s the updated graph, where I set the index of new and used car prices to a value of 1.0 in January 2020.  The underlying data are from the Bureau of Labor Statistics.

Original post follows.

 

 

Continue reading Post #1836: Will used-car prices continue to fall?

Post #1835: Buying an EV grocery-getter. Boiling it down to a Leaf.

 

Edit:  Between the time I wrote this, and the time I actually bought a car (January 2024), the price of a lightly-used Bolt had fallen so much that I bought a Bolt instead of a Leaf (Post #1924 ).

I’m trying to replace the gas vehicle I got rid of, about a year and a half ago, with an EV (electric vehicle).

Bottom line:  Well-used Nissan Leaf is the best fit, for my needs. Continue reading Post #1835: Buying an EV grocery-getter. Boiling it down to a Leaf.